/**********
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)

This library is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
more details.

You should have received a copy of the GNU Lesser General Public License
along with this library; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
**********/
// "liveMedia"
// Copyright (c) 1996-2018 Live Networks, Inc.  All rights reserved.
// Common routines for opening/closing named input files
// Implementation

#include "include/InputFile.hh"
#include <string.h>

FILE *OpenInputFile(UsageEnvironment &env, char const *fileName) {
    FILE *fid;

    // Check for a special case file name: "stdin"
    if (strcmp(fileName, "stdin") == 0) {
        fid = stdin;
#if (defined(__WIN32__) || defined(_WIN32)) && !defined(_WIN32_WCE)
        _setmode(_fileno(stdin), _O_BINARY); // convert to binary mode
#endif
    } else {
        fid = fopen(fileName, "rb");
        if (fid == NULL) {
            env.setResultMsg("unable to open file \"", fileName, "\"");
        }
    }

    return fid;
}

void CloseInputFile(FILE *fid) {
    // Don't close 'stdin', in case we want to use it again later.
    if (fid != NULL && fid != stdin) fclose(fid);
}

u_int64_t GetFileSize(char const *fileName, FILE *fid) {
    u_int64_t fileSize = 0; // by default

    if (fid != stdin) {
#if !defined(_WIN32_WCE)
        if (fileName == NULL) {
#endif
            if (fid != NULL && SeekFile64(fid, 0, SEEK_END) >= 0) {
                fileSize = (u_int64_t) TellFile64(fid);
                if (fileSize == (u_int64_t) -1) fileSize = 0; // TellFile64() failed
                SeekFile64(fid, 0, SEEK_SET);
            }
#if !defined(_WIN32_WCE)
        } else {
            struct stat sb;
            if (stat(fileName, &sb) == 0) {
                fileSize = sb.st_size;
            }
        }
#endif
    }

    return fileSize;
}

int64_t SeekFile64(FILE *fid, int64_t offset, int whence) {
    if (fid == NULL) return -1;

    clearerr(fid);
    fflush(fid);
#if (defined(__WIN32__) || defined(_WIN32)) && !defined(_WIN32_WCE)
    return _lseeki64(_fileno(fid), offset, whence) == (int64_t)-1 ? -1 : 0;
#else
#if defined(_WIN32_WCE)
    return fseek(fid, (long)(offset), whence);
#else
    return fseeko(fid, (off_t) (offset), whence);
#endif
#endif
}

int64_t TellFile64(FILE *fid) {
    if (fid == NULL) return -1;

    clearerr(fid);
    fflush(fid);
#if (defined(__WIN32__) || defined(_WIN32)) && !defined(_WIN32_WCE)
    return _telli64(_fileno(fid));
#else
#if defined(_WIN32_WCE)
    return ftell(fid);
#else
    return ftello(fid);
#endif
#endif
}

Boolean FileIsSeekable(FILE *fid) {
    if (SeekFile64(fid, 1, SEEK_CUR) < 0) {
        return False;
    }

    SeekFile64(fid, -1, SEEK_CUR); // seek back to where we were
    return True;
}
